1/*
2  Some of this code is credited to Linux USB open source files that are
3  distributed with Linux.
4
5  Copyright:	2007 Metrologic Instruments. All rights reserved.
6  Copyright:	2011 Azimut Ltd. <http://azimutrzn.ru/>
7*/
8
9#include <linux/kernel.h>
10#include <linux/tty.h>
11#include <linux/module.h>
12#include <linux/usb.h>
13#include <linux/errno.h>
14#include <linux/slab.h>
15#include <linux/tty_driver.h>
16#include <linux/tty_flip.h>
17#include <linux/moduleparam.h>
18#include <linux/spinlock.h>
19#include <linux/uaccess.h>
20#include <linux/usb/serial.h>
21
22#define DRIVER_DESC "Metrologic Instruments Inc. - USB-POS driver"
23
24/* Product information. */
25#define FOCUS_VENDOR_ID			0x0C2E
26#define FOCUS_PRODUCT_ID_BI		0x0720
27#define FOCUS_PRODUCT_ID_UNI		0x0700
28
29#define METROUSB_SET_REQUEST_TYPE	0x40
30#define METROUSB_SET_MODEM_CTRL_REQUEST	10
31#define METROUSB_SET_BREAK_REQUEST	0x40
32#define METROUSB_MCR_NONE		0x08	/* Deactivate DTR and RTS. */
33#define METROUSB_MCR_RTS		0x0a	/* Activate RTS. */
34#define METROUSB_MCR_DTR		0x09	/* Activate DTR. */
35#define WDR_TIMEOUT			5000	/* default urb timeout. */
36
37/* Private data structure. */
38struct metrousb_private {
39	spinlock_t lock;
40	int throttled;
41	unsigned long control_state;
42};
43
44/* Device table list. */
45static const struct usb_device_id id_table[] = {
46	{ USB_DEVICE(FOCUS_VENDOR_ID, FOCUS_PRODUCT_ID_BI) },
47	{ USB_DEVICE(FOCUS_VENDOR_ID, FOCUS_PRODUCT_ID_UNI) },
48	{ }, /* Terminating entry. */
49};
50MODULE_DEVICE_TABLE(usb, id_table);
51
52/* UNI-Directional mode commands for device configure */
53#define UNI_CMD_OPEN	0x80
54#define UNI_CMD_CLOSE	0xFF
55
56static inline int metrousb_is_unidirectional_mode(struct usb_serial_port *port)
57{
58	__u16 product_id = le16_to_cpu(
59		port->serial->dev->descriptor.idProduct);
60
61	return product_id == FOCUS_PRODUCT_ID_UNI;
62}
63
64static int metrousb_send_unidirectional_cmd(u8 cmd, struct usb_serial_port *port)
65{
66	int ret;
67	int actual_len;
68	u8 *buffer_cmd = NULL;
69
70	if (!metrousb_is_unidirectional_mode(port))
71		return 0;
72
73	buffer_cmd = kzalloc(sizeof(cmd), GFP_KERNEL);
74	if (!buffer_cmd)
75		return -ENOMEM;
76
77	*buffer_cmd = cmd;
78
79	ret = usb_interrupt_msg(port->serial->dev,
80		usb_sndintpipe(port->serial->dev, port->interrupt_out_endpointAddress),
81		buffer_cmd, sizeof(cmd),
82		&actual_len, USB_CTRL_SET_TIMEOUT);
83
84	kfree(buffer_cmd);
85
86	if (ret < 0)
87		return ret;
88	else if (actual_len != sizeof(cmd))
89		return -EIO;
90	return 0;
91}
92
93static void metrousb_read_int_callback(struct urb *urb)
94{
95	struct usb_serial_port *port = urb->context;
96	struct metrousb_private *metro_priv = usb_get_serial_port_data(port);
97	unsigned char *data = urb->transfer_buffer;
98	int throttled = 0;
99	int result = 0;
100	unsigned long flags = 0;
101
102	dev_dbg(&port->dev, "%s\n", __func__);
103
104	switch (urb->status) {
105	case 0:
106		/* Success status, read from the port. */
107		break;
108	case -ECONNRESET:
109	case -ENOENT:
110	case -ESHUTDOWN:
111		/* urb has been terminated. */
112		dev_dbg(&port->dev,
113			"%s - urb shutting down, error code=%d\n",
114			__func__, urb->status);
115		return;
116	default:
117		dev_dbg(&port->dev,
118			"%s - non-zero urb received, error code=%d\n",
119			__func__, urb->status);
120		goto exit;
121	}
122
123
124	/* Set the data read from the usb port into the serial port buffer. */
125	if (urb->actual_length) {
126		/* Loop through the data copying each byte to the tty layer. */
127		tty_insert_flip_string(&port->port, data, urb->actual_length);
128
129		/* Force the data to the tty layer. */
130		tty_flip_buffer_push(&port->port);
131	}
132
133	/* Set any port variables. */
134	spin_lock_irqsave(&metro_priv->lock, flags);
135	throttled = metro_priv->throttled;
136	spin_unlock_irqrestore(&metro_priv->lock, flags);
137
138	/* Continue trying to read if set. */
139	if (!throttled) {
140		usb_fill_int_urb(port->interrupt_in_urb, port->serial->dev,
141				 usb_rcvintpipe(port->serial->dev, port->interrupt_in_endpointAddress),
142				 port->interrupt_in_urb->transfer_buffer,
143				 port->interrupt_in_urb->transfer_buffer_length,
144				 metrousb_read_int_callback, port, 1);
145
146		result = usb_submit_urb(port->interrupt_in_urb, GFP_ATOMIC);
147
148		if (result)
149			dev_err(&port->dev,
150				"%s - failed submitting interrupt in urb, error code=%d\n",
151				__func__, result);
152	}
153	return;
154
155exit:
156	/* Try to resubmit the urb. */
157	result = usb_submit_urb(urb, GFP_ATOMIC);
158	if (result)
159		dev_err(&port->dev,
160			"%s - failed submitting interrupt in urb, error code=%d\n",
161			__func__, result);
162}
163
164static void metrousb_write_int_callback(struct urb *urb)
165{
166	struct usb_serial_port *port = urb->context;
167
168	dev_warn(&port->dev, "%s not implemented yet.\n",
169		__func__);
170}
171
172static void metrousb_cleanup(struct usb_serial_port *port)
173{
174	dev_dbg(&port->dev, "%s\n", __func__);
175
176	usb_unlink_urb(port->interrupt_in_urb);
177	usb_kill_urb(port->interrupt_in_urb);
178
179	metrousb_send_unidirectional_cmd(UNI_CMD_CLOSE, port);
180}
181
182static int metrousb_open(struct tty_struct *tty, struct usb_serial_port *port)
183{
184	struct usb_serial *serial = port->serial;
185	struct metrousb_private *metro_priv = usb_get_serial_port_data(port);
186	unsigned long flags = 0;
187	int result = 0;
188
189	dev_dbg(&port->dev, "%s\n", __func__);
190
191	/* Make sure the urb is initialized. */
192	if (!port->interrupt_in_urb) {
193		dev_err(&port->dev, "%s - interrupt urb not initialized\n",
194			__func__);
195		return -ENODEV;
196	}
197
198	/* Set the private data information for the port. */
199	spin_lock_irqsave(&metro_priv->lock, flags);
200	metro_priv->control_state = 0;
201	metro_priv->throttled = 0;
202	spin_unlock_irqrestore(&metro_priv->lock, flags);
203
204	/* Clear the urb pipe. */
205	usb_clear_halt(serial->dev, port->interrupt_in_urb->pipe);
206
207	/* Start reading from the device */
208	usb_fill_int_urb(port->interrupt_in_urb, serial->dev,
209			  usb_rcvintpipe(serial->dev, port->interrupt_in_endpointAddress),
210			   port->interrupt_in_urb->transfer_buffer,
211			   port->interrupt_in_urb->transfer_buffer_length,
212			   metrousb_read_int_callback, port, 1);
213	result = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
214
215	if (result) {
216		dev_err(&port->dev,
217			"%s - failed submitting interrupt in urb, error code=%d\n",
218			__func__, result);
219		goto exit;
220	}
221
222	/* Send activate cmd to device */
223	result = metrousb_send_unidirectional_cmd(UNI_CMD_OPEN, port);
224	if (result) {
225		dev_err(&port->dev,
226			"%s - failed to configure device, error code=%d\n",
227			__func__, result);
228		goto exit;
229	}
230
231	dev_dbg(&port->dev, "%s - port open\n", __func__);
232exit:
233	return result;
234}
235
236static int metrousb_set_modem_ctrl(struct usb_serial *serial, unsigned int control_state)
237{
238	int retval = 0;
239	unsigned char mcr = METROUSB_MCR_NONE;
240
241	dev_dbg(&serial->dev->dev, "%s - control state = %d\n",
242		__func__, control_state);
243
244	/* Set the modem control value. */
245	if (control_state & TIOCM_DTR)
246		mcr |= METROUSB_MCR_DTR;
247	if (control_state & TIOCM_RTS)
248		mcr |= METROUSB_MCR_RTS;
249
250	/* Send the command to the usb port. */
251	retval = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
252				METROUSB_SET_REQUEST_TYPE, METROUSB_SET_MODEM_CTRL_REQUEST,
253				control_state, 0, NULL, 0, WDR_TIMEOUT);
254	if (retval < 0)
255		dev_err(&serial->dev->dev,
256			"%s - set modem ctrl=0x%x failed, error code=%d\n",
257			__func__, mcr, retval);
258
259	return retval;
260}
261
262static int metrousb_port_probe(struct usb_serial_port *port)
263{
264	struct metrousb_private *metro_priv;
265
266	metro_priv = kzalloc(sizeof(*metro_priv), GFP_KERNEL);
267	if (!metro_priv)
268		return -ENOMEM;
269
270	spin_lock_init(&metro_priv->lock);
271
272	usb_set_serial_port_data(port, metro_priv);
273
274	return 0;
275}
276
277static int metrousb_port_remove(struct usb_serial_port *port)
278{
279	struct metrousb_private *metro_priv;
280
281	metro_priv = usb_get_serial_port_data(port);
282	kfree(metro_priv);
283
284	return 0;
285}
286
287static void metrousb_throttle(struct tty_struct *tty)
288{
289	struct usb_serial_port *port = tty->driver_data;
290	struct metrousb_private *metro_priv = usb_get_serial_port_data(port);
291	unsigned long flags = 0;
292
293	dev_dbg(tty->dev, "%s\n", __func__);
294
295	/* Set the private information for the port to stop reading data. */
296	spin_lock_irqsave(&metro_priv->lock, flags);
297	metro_priv->throttled = 1;
298	spin_unlock_irqrestore(&metro_priv->lock, flags);
299}
300
301static int metrousb_tiocmget(struct tty_struct *tty)
302{
303	unsigned long control_state = 0;
304	struct usb_serial_port *port = tty->driver_data;
305	struct metrousb_private *metro_priv = usb_get_serial_port_data(port);
306	unsigned long flags = 0;
307
308	dev_dbg(tty->dev, "%s\n", __func__);
309
310	spin_lock_irqsave(&metro_priv->lock, flags);
311	control_state = metro_priv->control_state;
312	spin_unlock_irqrestore(&metro_priv->lock, flags);
313
314	return control_state;
315}
316
317static int metrousb_tiocmset(struct tty_struct *tty,
318			     unsigned int set, unsigned int clear)
319{
320	struct usb_serial_port *port = tty->driver_data;
321	struct usb_serial *serial = port->serial;
322	struct metrousb_private *metro_priv = usb_get_serial_port_data(port);
323	unsigned long flags = 0;
324	unsigned long control_state = 0;
325
326	dev_dbg(tty->dev, "%s - set=%d, clear=%d\n", __func__, set, clear);
327
328	spin_lock_irqsave(&metro_priv->lock, flags);
329	control_state = metro_priv->control_state;
330
331	/* Set the RTS and DTR values. */
332	if (set & TIOCM_RTS)
333		control_state |= TIOCM_RTS;
334	if (set & TIOCM_DTR)
335		control_state |= TIOCM_DTR;
336	if (clear & TIOCM_RTS)
337		control_state &= ~TIOCM_RTS;
338	if (clear & TIOCM_DTR)
339		control_state &= ~TIOCM_DTR;
340
341	metro_priv->control_state = control_state;
342	spin_unlock_irqrestore(&metro_priv->lock, flags);
343	return metrousb_set_modem_ctrl(serial, control_state);
344}
345
346static void metrousb_unthrottle(struct tty_struct *tty)
347{
348	struct usb_serial_port *port = tty->driver_data;
349	struct metrousb_private *metro_priv = usb_get_serial_port_data(port);
350	unsigned long flags = 0;
351	int result = 0;
352
353	dev_dbg(tty->dev, "%s\n", __func__);
354
355	/* Set the private information for the port to resume reading data. */
356	spin_lock_irqsave(&metro_priv->lock, flags);
357	metro_priv->throttled = 0;
358	spin_unlock_irqrestore(&metro_priv->lock, flags);
359
360	/* Submit the urb to read from the port. */
361	port->interrupt_in_urb->dev = port->serial->dev;
362	result = usb_submit_urb(port->interrupt_in_urb, GFP_ATOMIC);
363	if (result)
364		dev_err(tty->dev,
365			"failed submitting interrupt in urb error code=%d\n",
366			result);
367}
368
369static struct usb_serial_driver metrousb_device = {
370	.driver = {
371		.owner =	THIS_MODULE,
372		.name =		"metro-usb",
373	},
374	.description		= "Metrologic USB to Serial",
375	.id_table		= id_table,
376	.num_ports		= 1,
377	.open			= metrousb_open,
378	.close			= metrousb_cleanup,
379	.read_int_callback	= metrousb_read_int_callback,
380	.write_int_callback	= metrousb_write_int_callback,
381	.port_probe		= metrousb_port_probe,
382	.port_remove		= metrousb_port_remove,
383	.throttle		= metrousb_throttle,
384	.unthrottle		= metrousb_unthrottle,
385	.tiocmget		= metrousb_tiocmget,
386	.tiocmset		= metrousb_tiocmset,
387};
388
389static struct usb_serial_driver * const serial_drivers[] = {
390	&metrousb_device,
391	NULL,
392};
393
394module_usb_serial_driver(serial_drivers, id_table);
395
396MODULE_LICENSE("GPL");
397MODULE_AUTHOR("Philip Nicastro");
398MODULE_AUTHOR("Aleksey Babahin <tamerlan311@gmail.com>");
399MODULE_DESCRIPTION(DRIVER_DESC);
400